1. Field of the Invention
This invention pertains generally to a child resistant dispensing closure. More particularly, the invention relates to a child resistant dispensing closure of the type comprising a closure member and a lid member mounted upon the closure member in such a way as to be capable of being manipulated so as to prevent or permit material being moved through the dispensing closure. The invention contemplates a dispensing closure of the foregoing type wherein manipulation of the lid member from a closed position, wherein material is prevented from passing through the dispensing closure, to an open position, wherein material is allowed to pass through the dispensing closure and, hence, be dispensed, is accomplished only by deformation of a portion of the closure member. The requirement for specific deformation action effectively precludes access by children to the contents of a container to which the dispensing closure is attached.
The term "dispensing closure" is commonly utilized to designate closures which are normally adapted for attachment to the necks of containers such as bottles, tubes, or the like. Such dispensing closures, as are commonly known, generally include a closure member adapted to be secured to or formed integrally with a container and a lid member which is mounted on the closure member for movement between open and closed positions. In the open position, material can be moved through an opening in the closure member, while in the closed position such opening is closed off or sealed.
It has been previously recognized that the utility of a dispensing closure in many different types of applications can be enhanced or improved by constructing such a closure so that the lid member is normally held in an open position once it has been moved into such position, until such time as deliberate force is applied by the user to close such a lid member.
Various expedients and structures have been utilized in the prior art in order to obtain the foregoing attributes. Examples of dispensing closures of this type are found in U.S. Pat. No. 4,172,540 and in U.S. Pat. No. 4,220,248. U.S. Pat. No. 4,172,540, issued on Oct. 30, 1979 to Erichson, discloses a dispensing closure having a cap and a lid mounted thereon by means of a spring. The spring serves to hold the lid relative to the top of the cap so that the lid is held against movement when in the open position. U.S. Pat. No. 4,220,248, issued on Sept. 2, 1980 to Wilson et al, is directed to a closure member and lid wherein a spring structure and a cam structure cooperate to hold the lid in an open or closed position.
The latter dispensing closure structures are considered to be highly desirable from a unitarian standpoint in that the lid member is prevented from interfering with the discharge of material through such closures. Additionally, dispensing closures as so described may be easily and conveniently manufactured at a nominal cost and are of such a character that they afford facility of use over a prolonged period. Moreover, these dispensing closures are advantageous because of their simplicity, because the manner in which they are constructed makes it possible to utilize them without danger of damage during handling, installation and the like, and because they are aesthetically satisfying.
While the attributes of the foregoing dispensing closures are numerous, the need exists to provide such closures with an effective means for preventing unwanted access to potentially harmful contents of the container with which the closure is associated. The need for dispensing closures with child resistant features is precipitated by the extensive home and personal usage and consumption of potentially injurious substances such as medicaments, pharmaceuticals, cosmetics, cleaning preparations and the like. Thus, the need exists for a dispensing closure that not only possess the diverse attributes discussed above, but which is relatively difficult to open so that comparatively young children or those of reduced mental capacity cannot open them under normal circumstances. However, the dispensing closure must also be sufficiently easy to open so that it may be operated by individuals of normal mental capacity, even if such individuals do not possess what may be regarded as normal physical strengths.
Previous attempts to provide dispensing closures of a child resistant character have often resulted in structures which, due to their complexity, were prohibitively expensive to manufacture for commercial utilization. Additionally, complicated construction often rendered the closure difficult to operate, even by an adult, requiring complicated manipulations and/or considerable force. Those closures wherein the child resistant feature depends upon the application of relatively great strength, are particularly flawed in that a small child may be stronger than an elderly person or someone weakened by illness and the closure, therefore, inevitably fails to fulfill its child resistant purpose. The child resistant features which require unusually complex manipulations are, in reality, impractical to use and are destined to fail in gaining commercial acceptance. The more simple structures which have been adopted have generally proved to be disappointing in responding to child resistant demands, being easily penetrable, deliberately or inadvertently, by an average child.
The instant invention addresses the foregoing problems and deficiencies by providing a dispensing closure characterized by a lid member and a closure member, wherein the lid member is adapted to be maintained in an open position in which the lid member does not interfere with the dispensing of a product through the closure member and wherein the lid member may be moved from the closed position to the open dispensing position only by applying manual pressure, by means of the user's thumb, to a portion of the closure member. This application of manual pressure causes the closure member to be deformed so as to produce a small separation of the lid member and the closure member from the position wherein said members normally abut in the closed position. While continuing to apply this manual compressive force, the user may then, with the opposite free hand, engage a portion of the lid member by means of a finger, fingernail or small object in order to move the lid member upwardly into the open position.
The requirement for a manual compressive force in order to operate the dispensing closure presents a reliable and effective child resistant feature in that it addresses and overcomes the universal inherent tendency of a child to separate parts by directly pulling them apart. Additionally, this force or pressure must be applied to a specific portion of the closure member by the finger, and preferably the thumb, of the user while the dispensing closure is grasped by the hand. It is highly improbable that a child or other individual of impaired mental ability would discover, intentionally or inadvertently, the very limited area to which the manual force must be applied. Furthermore, the instant dispensing closure necessitates for operation the additional action, simultaneous with the application of the manual force, of engaging and moving the lid member with the opposite hand. This series of movement requires for execution such dexterity, coordination and mental skill that are normally beyond the capabilities of the ordinary child or other individual of reduced mental ability.
2. Description of the Prior Art
Dispensing closures of the broad type wherein a portion of the closure is required to be deformed by the user as a step in gaining access to the contents of the associated container are known in the prior art. For example, U.S. Pat. No. 3,528,581, issued on Apr. 29, 1968 to Lange, Jr., discloses a safety cap for a container wherein access to the contents of the receptacle is gained by manually pressing the collar of the cap in the direction of the receptacle so that a closure member can be pulled away from engagement with the mouth of the receptacle.
U.S. Pat. No. 3,603,470, issued on Sept. 7, 1971 to Armour shows a closure which is unlocked by applying an inward compressive force to the outer surface of the skirt of the closure to disengage the skirt from an overcap hingedly connected thereto.
U.S. Pat. No. 3,790,015, issued Feb. 5, 1974 to Imamura, is directed to a container having a cap which may be removed by pressing inwardly on the container wall.
U.S. Pat. No. 3,850,326, issued on Nov. 26, 1974 to Ryles, discloses a safety closure having an opening formed therein and a snap-on lip adapted to open and close the opening. A portion of the outer surface of the closure is displaceable inwardly to allow a finger of the user to engage under the lid to overcome its snap action.
U.S. Pat. No. 4,010,875, issued on Mar. 8, 1977 to Babiol, teaches a stoppering device hingedly connected to a closure cap. Manual pressure on a peak of the cap causes the latter to pivot with respect to the stoppering device.
U.S. Pat. No. 4,209,100, issued June 24, 1980 to Uhlig, discloses a safety closure having a wall segment adapted to be pressed inwardly for freeing a locking flap from sealing engagement with an opening in the closure.
U.S. Pat. No. 4,513,888, issued Apr. 30, 1985 to Curry, discloses a dispensing cap having a flexible panel which must be manually depressed inwardly to expose a portion of the cover.
The prior art fails to provide a dispensing closure characterized by a lid member that is prevented from interfering with the associated closure member when the lid member is in the open position, and wherein the lid member may be manipulated from a closed position to the open position by application of a manual compressive force by means of the user's finger to a specific portion of the closure member while simultaneously engaging the lid member with the opposite hand to move the lid member upwardly with respect to the closure member to achieve the open dispensing position.